How long until calories absorb?

I have a question for anyone who can answer it. I have been battling some crazy stomach virus that has made me vomit more than I care to. I am on a diet and pay close attention to my caloric intake. I haven't had much to eat today, and was hoping most of my calories from dinner had absorbed before it came back up.(30-40 minutes later) I am trying to avoid starvation mode, so I would like my dinner to count for something. Does anyone know how long after a meal most calories have been absorbed?

More than 30-40 minutes, unfortunately. Most of the absorption takes place in your small intestine, and it generally takes 4-5 hours for food to pass from your stomach into the first part of your small intestine.

Don't try to force anything down if you're sick, though. Consider your normal metabolism on holiday and just eat what you can handle. Hope you feel better soon!

You won't go into starvation mode b/c you are in the midst of a brief stomach virus as long as soon as you keep things down you go back to a normal routine as possible and eat well. Take care of yourself and if the stomach problems and vomiting don't go away in a day or two please consult your physician as it may be something else.

Sorry, I'm not aware of the "chewing & spitting" debate ... you'll have to fill me in. Digestion of starches begins in the mouth from salivary enzymes, but I'm not aware that calories are absorbed then ... sugars need to be broken down further and processed before they are available for energy. Here is a good summary of the digestive process.